There has long been an idealistic, even utopian, streak in American society that has held that the abnegation of power by the United States will inspire other countries to follow suit. This view became ascendant during the 1920s, when Republican administrations naively negotiated a series of naval arms-reduction treaties and, as the piece de resistance, the Kellogg-Briand Pact of 1928, which outlawed war “as an instrument of national policy.” When the biggest war in history began a decade later, the United States paid a high price for its lack of preparedness.

Last year, a pair of Yale University law professors published a book arguing that Kellogg-Briand wasn’t the failure it was universally assumed to be. They said the treaty was responsible for the decline of interstate conflict after 1945. But their argument wasn’t persuasive. The real reasons conventional warfare became less common after World War II had more to do with revulsion against total war, the creation of alliances such as NATO, the spread of democracy and free trade — and, above all, the ability and willingness of the United States to deter aggressors with its conventional and nuclear forces.

That history should be kept in mind amid the criticism of the Trump administration’s Nuclear Posture Review, which calls for modernizing and expanding the U.S. nuclear arsenal. President Trump’s plans have enraged “nuclear zero” advocates who think the United States should set an example for the world by downsizing its nuclear stockpile. This has become a trendy cause in recent years, winning the support of esteemed elder statesmen such as George P. Shultz, Henry Kissinger, William J. Perry and Sam Nunn. President Barack Obama endorsed the goal of a nuclear-free world in 2009 in a speech in Prague and the following year concluded the New Start Treaty with Russia, limiting each side to 1,550 deployed warheads. That’s down 85 percent from the heights of the Cold War.

Unfortunately, hopes that other countries would emulate the United States’ self-restraint have not been fulfilled. Russia, China and North Korea are all expanding their nuclear arsenals. Iran is held in check only temporarily by the nuclear deal — and maybe not for long, if Trump unwisely blows it up. Russia, a country that Trump won’t criticize, is a particular focus of concern for Defense Secretary Jim Mattis. His Nuclear Posture Review bluntly calls out Russia for violating the 1987 Intermediate-Range Nuclear Forces Treaty by building a new ground-launched cruise missile and warns that it is “also developing at least two new intercontinental range systems, a hypersonic glide vehicle, and a new intercontinental, nuclear-armed, nuclear-powered, undersea autonomous torpedo.”

Not only is Russia building more atomic weapons, but also it is showing an alarming willingness to threaten the use of those weapons. As the review notes, Russia may “rely on threats of limited nuclear first use, or actual first use, to coerce us, our allies, and our partners into terminating a conflict on terms favorable to Russia. Moscow apparently believes that the United States is unwilling to respond to Russian employment of tactical nuclear weapons with strategic nuclear weapons.”

The Nuclear Posture Review won’t affect the New Start limits on the number of U.S. strategic warheads. But it does propose to counter Russia’s nuclear buildup by enhancing our tactical — i.e., smaller — nuclear weapons. It calls for the deployment of low-yield warheads on submarine-launched ballistic missiles, the development of a new submarine-launched nuclear cruise missile and the retrofitting of F-35s to carry nuclear bombs. Mattis suggests that the new weapons could serve as bargaining chips with the Russians.

Beyond that, Mattis proposes to upgrade an aging and dilapidated U.S. nuclear infrastructure. As the New York Times noted in 2014, “Its oldest elements, some dating to 1943, have long struggled with fires, explosions and workplace injuries. This March, a concrete roof collapsed in Tennessee. More recently, chunks of ceiling clattered down a stairwell there, and employees were told to wear hard hats.”

Obama already promised, as part of the deal to ratify New Start, to spend more than $1 trillion over the next 30 years to modernize U.S. nuclear systems. The Trump Nuclear Posture Review essentially affirms that pledge, minus the utopian language about someday, somehow eliminating nuclear weapons. It doesn’t warrant hysterical criticism with headlines such as “Nuclear Nuts: Trump’s New Policy Hypes The Threat and Brings Us Closer to War.”

Granted, it’s terrifying to have Trump, the self-proclaimed “stable genius,” in control of the nuclear codes. He has engaged in nuclear saber-rattling by bragging that his nuclear button is “much bigger & more powerful” than Kim Jong Un’s and threatening to rain down “fire and fury.” This is unprecedented and irresponsible behavior.

But Trump won’t be president forever. We should not let justifiable concerns about his mental stability lead us to make long-term decisions that will undercut the nuclear deterrent commanded by his successors — who, one hopes, will be better qualified to wield that awesome power.